Sandblasting machine



SANDBLASTINGMACHINE Filed No 13, 1939 2 Sheets-Sheet 1 lNVEN'i'OR'FH.ROSEZZ8 ATTORNEY 1939 2 Sheets-Sheet 2 INVENTOR .FTHRoseZZe NEY F.H. ROSELLE SANDBLASTING MACHINE Filed Nov. 15

Nov. 4,.1941.

Patented Nov. 4, 1941 TAES r QFF! This invention relates in general tosand blasting apparatus, and in particular the invention is directed toimproved mechanism in apparatus of the type described to feed the sandinto the stream of compressed air.

Heretofore, the general practice has been to feed the sand from a tankor reservoir through a lead pipe into the lateral side of a T-fitting;said T-fitting being interposed in the compressed air line. Thisarrangement has been subject to the objection that there is a tendencyfor the sand to plug in the T-fitting during operation of the apparatus.

It is therefore the principal object of this invention to providemechanism which is arranged to prevent plugging of the sand in any partof the apparatus, such object being accomplished through the medium of aunique sand and air mixing assembly.

Another object of the invention is to provide mechanism for theregulation of the proportion of sand mixed with the compressed air andfed into the hose and sand blast nozzle of the apparatus.

A further object of the invention is to provide means in the apparatusarranged so that the supply of sand can be entirely shut ofi whendesired, so that air alone passes into the sand blast hose and nozzle.

A further object of the invention is to produce a simple and inexpensivedevice and yet one which will be exceedingly efiective for the purposefor which it is designed.

These objects I accomplish by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claims.

In the drawings similar characters of reference indicate correspondingparts in the several views:

Figure 1 is a side elevation of the apparatus.

Figure 2 is a fragmentary sectional elevation of the apparatus.

Referring now more particularly to the characters of reference on thedrawings, the device comprises a vertical and elongated tank orreservoir I, the bottom of which is of inverted frustoconicalconfiguration, as at 2. This tank is supported by suitable legs 3, andis provided on opposed sides with carrying handles 4 which normallydepend from pivots 5 carried by brackets 6, said brackets including stopelements 1 adapted to engage the inner ends of the handles and to limitoutward and upward swinging movement of said handles to a horizontalposition, as clearly shown in dotted lines in Fig. 1.

At its upper end, but offset from the vertical axis thereof, the tank Iis provided with a filling neck 8 which includes a pressure-tight butremovable cap indicated generally at 9.

I A compressed air supply hose l0 extends from the source of compressedair (not shown) to a point beneath the tank I, and from said point isconnected with a fitting II on the bottom of the inverted frusto-conicalportion 2 of the tank by means of an elbow l2, union l3, and nipple M; avalve I5 being interposed between the end of the hose I0 and elbow l2. Avertical nozzle or jet I6 is fitted within nipple M and extends from aflanged lower end I! secured in the union I3 upward to a terminationwithin'the tank portion 2 some distance above fitting I l. r

A pipe l8 having an internal diameter somewhat greater than the diameterof the upper or discharge end of nozzle I6 is disposed axially andvertically in tank I; the lower end of said pipe I8 being disposedadjacent nozzle l6, while the upper end portion of the pipe slidablyextends through and projects some distance beyond a packing gland I9inthe upper end of the tank I. Within the tank I, the pipe I8 isslidably supported by means of a spider 20.

An upwardly opening cup 2| is formed integral with thenut 22 of packinggland l9, and surrounds a pipe I8 above said gland l9; this cup 2| atits upper edge being formed with an outwardly projecting annular flange23. An exteriorlythreaded sleeve 24 is fixed on pipe l8 by means of aset screw 25, and extends upward about said pipe l8 from within cup 2|.A hand wheel 26 is threaded on sleeve 24 above cup 2|, and this handwheel 26 is provided with an-annular collar 2'! secured in place bybolts 28; such collar engaging beneath cup flange 23.

At its upper end, pipe I8 is provided with a bell reducer 29 and aflexible hose 39 is connected at one end by suitable means insaidreducer 29. A swinging hose supporting bracket 3| is formed with a fork32 mounted on pipe [8 between sleeve 24 and reducer 29; said bracket 3|above the fork curving upwardly and outwardly and at its upper end beingformed with an eye 33 through which the hose 30 projects. This swingingbracket 3| prevents kinking or rupturing of the hose adjacent thereducer 29, and which would otherwise occur when the hose 30 was swungabout during a sand blasting operation. The sand blast nozzle (notshown) is attached to the free end of hose 30 as is usual.

In operation, a quantity of sand is disposed in tank I through fillingneck 8, and cap 9 is then secured in place in pressure-tight connectionwith said neck. Thereafter, said valve I5 is opened and the compressedair from hose l passes through vertical jet I6 and blows into the lowerend of pipe I8. As the compressed air blows through into the lower endof pipe I8, it carries with it a quantity of sand from the tank I, thelower end of said pipe l8 being spaced above the upper end of nozzle l6somewhat and so as to permit the sand to so pass into said pipe l8.

In order to regulate the amount of sand being carried into pipe l8 bythe force of the compressed air from jet l6, said pipe I8 is raised orlowered as desired, and this is accomplished by rotating hand wheel 26;rotation of the hand wheel 26 causing the sleeve 24 and connected pipeIE to raise Or lower, depending on the direction of rotation of the handwheel 26.

During operation of the apparatus, a head of compressed air builds up inthe upper portion of tank I above the surface of the supply of sand, andwhen the valve I is shut off to stop operation of the device, such headof compressed air would force a plug of sand into nozzle I6 and upwardinto pipe I8 if means were not provided to relieve such head of air. Toprovide such relief, a bleed opening 34 is formed in pipe [8 at a pointadjacent the upper end of tank I. When the valve I5 is closed, the headof compressed air in the tank I immediately bleeds out through opening34 and thus no plug of sand occurs in jet H5 or pipe l8.

If it is desired that compressed air alone shall pass into pipe 18, thehand wheel 26 is rotated in a direction to lower pipe l8 until the lowerend of said pipe projects over the upper end portion of nozzle l6, andrests on the bottom or lower end of tank portion 2.

From the foregoing description it will be readily seen that I haveproduced such a device as substantially fulfills the objects of theinvention as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetail may be resorted to as do not form a departure from the spirit ofthe invention, as defined by the appended claims.

Having thus described my invention, what I claim as new and useful anddesire to secure by Letters Patent is:

1. In sand blasting apparatus, a sand receiving tank, a vertical nozzleprojecting into the tank through the bottom thereof, a pipe projectingthrough the upper end of the tank and depending to a termination at itslower end adjacent but normally spaced from said nozzle, the

nozzle and said pipe being disposed in axial alignment, means mountingthe pipe for vertical sliding movement, and manually operative means 5to effect such movement from exteriorly of the tank.

2. In sand blasting apparatus, a sand receiving tank, a nozzle in thetank, means to supply compressed air to said nozzle, a pipe extendinginto the tank and terminating at one end in adjacent axially alinedrelation to the discharge end of said nozzle, means mounting said nozzleand pipe for relative axial movement at their adjacent ends, andmanually operative means to effect such movement from exteriorly of thetank.

3. In sand blasting apparatus, a sand receiving tank, a nozzle in thetank, means to supply compressed air to said nozzle, a pipe extendinginto the tank and terminating at one end in adjacent axially alinedrelation to the discharge end of said nozzle, means mounting the pipe inconnection with the tank for axial movement at said one end, and a handmember movably mounted in connection with the tank exteriorly 25 thereofand operative to effect said axial movement of the pipe at said one end.

4. In sand blasting apparatus, a sand receiving tank, a nozzle in thetank, means to supply compressed air to said nozzle, a pipe extendinginto the tank and terminating at one end in adjacent axially alinedrelation to the discharge end of said nozzle, and means mounting saidnozzle and pipe for relative axial movement at their adjacent ends; saidlast named means comprising a sleeve fixed on the pipe exteriorly of thetank, and a hand wheel threaded on said sleeve and mounted in rotatablebut axially immovable relation to said sleeve.

5. In sand blasting apparatus, a sand receiving tank, a nozzle in thetank, means to supply compressed air to said nozzle, a pipe extendinginto the tank and terminating at one end in adjacent axially alinedrelation to the discharge end of said nozzle, and means mounting saidnozzle and pipe for relative axial movement at their adjacent ends; saidlast named means comprising a sleeve fixed on the pipe exteriorly of thetank, a hand wheel threaded on said sleeve, a packing gland on the tankthrough which said pipe slidably extends, an outwardly facing cup formedwith said packing gland and surrounding the pipe, the inner end of saidsleeve projecting into said cup, an annular flange formed on andprojecting laterally outward from the outer end of said cup, and anannular collar on the hand Wheel and engaging under said flange.

FREDRICK H. ROSELLE.

